The pathways of synthesis of sulfated mucopolysaccharides are being examined by means of cell free systems from mast cell tumors, chick embryo cartilage, and mast cells grown in tissue culture. Radioactive sugar nucleotides and PAPS 35 are being used as substrates. The cell components involved in these syntheses are being examined and characterized. Tadpole hyaluronidase is being investigated for the significance of its action during metamorphosis. The enzyme is being purified and substrate specificity is being determined. Cell components involved are being identified, and subcellular localization determined.